Buckstay arrangement for vapor generators and the like



Oct. 11, 1966 s. J. REALE 3,277,870

BUCKSTAY ARRANGEMENT FOR VAPOR GENERATORS AND THE LIKE,

Filed Dec. 30, 1965 5 Sheets-Sheet 1 Oct. 11, 1966 s. J. REALE ,2

BUCKSTAY ARRANGEMENT FOR VAPOR GENERATORS AND THE LIKE Filed Dec. ,19 5Sheets-Sheet 2 Q S "Q B S. J. REALE Oct. 11, 1966 BUCKSTAY ARRANGEMENTFOR VAPOR GENERATORS AND THE LIKE Filed Dec. 30, 1965 5 Sheets-Sheet 5\m ||||i1l1.l% Hwmmm nw mmd o 0 0d 0 o o M m \w 3 HM V w W M 3 1 v v U vwk v v v m6 v a v R ww a L a ooooooooooowr s L om a R H. .i l| w on ma m,ihhihnr .l| 1| lzn w 7. .11 w m @m a 3 a S. J. REALE BUCKSTAYARRANGEMENT FOR VAPOR GENERATORS AND THE LIKE Filed Dec. 30, 1965 5Sheets-Sheet 4 Oct. 11, 1966 s. J. REALE 3, 77,870

BUCKSTAY ARRANGEMENT FOR VAPOR GENERATORS AND THE LIKE Filed Dec. 30,-1965 5 Sheets-Sheet 5 United States Patent 3,277,870 BUCKSTAYARRANGEMENT FOR VAPUR GENERATORS AND THE LIKE Salvatore J. Reale, Wayne,N..l., assignor to Foster Wheeler Corporation, New York, N.Y., acorporation of New York Filed Dec. 30, 1965, Ser. No. 517,537 3 Claims.(Cl. 122-6) This invention relates to the construction of vaporgenerators and the like and, more particularly, to the construction ofan improved buckstay arrangement for vapor generators and the like.

In the construction of vapor generating units, the gas chamber of suchunits is generally enclosed by vertically oriented fluid-cooled tubeswhich form walls. Buckstays, in the form of I-beams, or other structuralshapes, gencrally encompass the generator engaging all four walls, andare arranged to take or withstand lateral forces imposed on the wall bywind, internal pressure, and other such forces.

In modern vapor generators, a wall construction for the combustionchamber and gas fi-ow passages is conventionally used in which thebuckstays are disposed outside of the generator wall insulation. In thisway, the buckstays are exposed to ambient temperature conditions. At onetime, such buckstay construction utilized a tension tie which waslocated behind the buckstays and was welded to the tubes. At eachcorner, a corner bracket was welded to the corner of the tube wall andalso to the two tension ties which meet at the respective corner.Linkages, oftentimes in the form of various bars and pins, connectedwith the corner bracket and the ends of the two adjacent buckstays. Thisconstruction, utilizing welded tension ties and corner brackets, is notonly expensive but generally requires very close tolerances,particularly in the linkages, which results in difliculties during fielderection.

A recent improvement over the earlier design has been the use of aplurality of suspended tension rods behind the buckstays which areconnected to the ends of the two adjacent buckstays. This design,although an improvement over the early construction, is still undulyexpensive and complex.

Therefore, it is an object of this invention to provide an improved walland buckstay arrangement which is simple and inexpensive to erect.

Another object is to provide an improved wall and buckstay arrangementwhich requires a minimum of shop assembly and parts.

A feature of this invention resides in the use of a single tension cableindependently suspended behind a buckstay. Each tension cable isconnected to the ends of the two buckstays at approximately right anglesto the respective tension cable. Since all the tension rods behind thebuckstays lie in a common plane, a cross-over means, preferably in theform of a turnbuckle, is utilized. The buckstays are suspended from thewalls of the Vapor generator so as to permit separate parallel movementof the wall and the buckstay. The tension rods are located within themeans for suspending the buckstays which suspension means includes ameans for retaining the tension rods against the wall of the vaporgenerator.

The invention may be better understood from the following detaileddescription considered in conjunction with the accompanying drawings inwhich:

FIGURE 1 is a perspective view partially broken away of a corner of avapor generating unit incorporating the novel buckstay arrangement inaccordance with this invention.

FIGURE 2 is a side elevation in cross section of a vapor generating unitwith the outside covering removed BETZflW Patented Oct. ll, 1966 iceincorporating a buckstay arrangement in accordance with this invention.

FIGURE 3 is a top sectional view of a steam generator utilizing theinvention and having the internal tubes removed.

FIGURE 4 is a cross-sectional view along line 44 of FIGURE 3 showing thedetails of a clip arrangement utilized in accordance with this inventionwith the insulation and outside covering removed.

FIGURE 5 is a cross-sectional view along line 5--5 of FIGURE 4.

FIGURE 6 is a partial top sectional view of a corner of a steamgenerator utilizing the invention and showing the position of theinvention and the steam generator when heated from operation.

FIGURE 7 is a partial top sectional view similar to FIGURE 6 but showingthe position of the invention and the steam generator when cold.

Although the vapor generator illustrated in FIGURE 2 is of relativelylow capacity, the invention is useful on generators of many sizes andalso for apparatus such as superheaters, economizers, and air heatexchangers where support of the components of the unit is required. Theoutside of the vapor generator includes four main enclosure walls 11which are vertically oriented. The four main enclosure walls 11 includetwo separate pairs of oppositely disposed vertical walls extendingbetween one another and joined together. The vapor generator is providedwith a fluid-cooled combustion chamber 12 fired by burners 14. Theburners 14 can burn any suitable fuel. The chamber 12 is enclosed inpart by a front wall 16 in which the burners 14 are located and a roof18, a floor 20, and a partition 22. The front wall 16, the roof 18, thefloor 2d, and the partition 22 are all formed with tubes 24 having fins26 welded between them. However, by omitting the fins 26 in the uppersection 28 of the partition 22, the hot gases of combustion flow out ofthe chamber 12. A superheater passageway 3t) is formed between thepartition 22 and a first wall 32. The hot gases leaving the chamber 12ow into the superheater passageway 30. A lower section 34 of the firstwall 32 also fabricated from the tubes 24 has the fins 26 removed topermit flow of the gases into an upward passageway 36 as shown by thedirectional arrows. The upward passageway 36 is formed between the firstwall 32 and a second wall 38. An upper section 40 of the second wall 38of tubes 24 has the fins 26 removed to permit flow of the gases into adownward passageway 42. The downward passageway 42 of the second wall 38of tubes 24 has the fins 26 removed to permit flow of the gases into thedownward passageway 42. The downward passageway 42 is formed between thesecond wall 38 and a rear wall 44 of tubes 24. An opening 46 located ata lower section of the rear wall 44 permits the hot gases to flow to astack (not shown). Located within the upward passage 36 and downwardpassage 42 are tubes 24 but without fins 26. Within the superheaterpassageway 30, a superheater bank 46 is located. On the opposite side ofthe partition 22, a reheater bank 48 is located. At the top of the vaporgenerator, the vapor-liquid mixture is collected in a steam drum 50 andthe liquid is returned through the tubes 24 to a water drum 52 at thebase of the generator. Two side walls 54 also formed from the tubes 24and fins 26 enclose the remaining sides of the steam generator. Thetubes 24 within the side walls 54, extend from lower side wall headers56, which are connected to the water drum 52 to upper side wall headers58, which in turn are connected to the steam drum 50. The four mainenclosure walls 11, previously referred to, include the front wall 16,the side walls 54, and the rear wall 44. Surrounding the main enclosurewalls 11 are buckstays 61. The buckstays 61 are located at two levels,namely a lower buckstay =32 arrangement 63 and an upper buckstayarrangement 69. The upper buckstay arrangement 69 and the lower buckstayarrangement 63 are similar except that in the lower arrangement 69, atruss 65 is utilized along the front wall 16 due to a wind box 67.

In the upper plane there is located along the front wall 16 a frontI-beam 60. Side I-beams 62, 64 are located along the two side walls 54.A rear I-beam 66 is located along the rear wall 44. At both ends of allthe buckstays 61 is a tubular connector 68 which is preferably securedto the buckstays 61 by welding. The ends of the buckstays 61 extend justslightly beyond the two walls adjoining the wall against whichrespective buckstay 61 is located. The tubular connectors 68 are locatedhorizontally with their longitudinal axis perpendicular to the plane ofthe wall against which their respective buckstay 61 is located. Thebuckstays 61 are placed with the webs 70 of the I-beams in a horizontalposition and with their outside flanges 72 and inside flanges 73vertically oriented. As best seen in FIGURES 4 and 5, there are weldedto the inside flanges 73 buckstay L-shaped clips 74. The sections 75 ofthe clips 74 welded to the inside flanges 73 are parallel to one anotherwhile the sections 76 perpendicular to the welded sections are alsoparallel to one another but pointing in opposite directions and awayfrom one another. Pairs of fin L-shaped clips 77 are welded to the fins26. The sections 78 of the clips 77 welded to the fins are approximatelyparallel with each other with one fin clip 77 directly above the otherfin clip 77 and with perpendicularly extending sections 79 beingparallel in a common plane and directed toward each other. Each pair ofbuckstay clips 74 is spaced to have the extending sections 76 of theangles 74 behind the extending sections 78 of the fin clips 77 and thebuckstay clips 74 extend a much larger distance along the buckstays 61to permit horizontal expansion of the I-beams 61. In this way theI-beams 61 are secured to the walls but are still able to movehorizontally in relationship to the wall behind it. The clips 77 arespaced about the walls 11 to provide adequate support for the buckstays61.

Located behind the buckstays 61 are tension rods 81. Suspended behindthe front I-beam 60 is a front tension rod 88. Suspended behind thefirst side I-beam 62 is a first side tension rod 82 while a second sidetension rod 84 is independently suspended behind the second side I-beam64. A rear cable 86 is located behind the rear I-beam 66. The sidetension rods 82, 84, which form one pair of tension rods, extend fromthe tubular members 68 attached to both ends of the front I-beam 60 andthe rear I-beam 66. The front and rear tension rods 80, 86, which formanother pair of tension rods, extend from the tubular members 68attached to both ends of the front I-beam 60 and the rear I-beam 66. Ateach corner, a turnbuckle 90 is located which has an opening 92 thereinsuificiently large to permit the tension rod 81 crossing it to fitthrough it. The use of the turnbuckles 90 is necessitated because thetension rods 81 are located in a common plane. By locating twoturnbuckles 90 in each of the two side tension rods 82, 84 the front andrear tension rods 80, 86 can pass through them. However, the turnbuckles90 could be located in the front and rear tension rods 80, 86 or in anycombination providing there is a turnbuckle 90 at each corner where twotension rods 81 cross. Both ends of the tension rods 81 are threaded andnuts 91 draw the tension rods 81 into tension between two I-beams 61.

Between the I-beam clips 74 and adjacent the inside flange 72 an angleor other strengthening member 92 is welded in place. Besidesstrengthening the clips 74 the .angle 92, as best seen in FIGURE 4,serves to maintain the tension rods 81 in sliding contact with thefin-tube enclosure walls 11 so that the tension rods 81 are heated bythe walls 11. As best seen in FIGURE 6, the tension rods 81 bowoutwardly at the ends when the steam generator is cold due to thepresence of angles 92 adjacent each corner. As also shown in FIGURE 6,the tension rods 81 straighten as the walls 11 expand from heating. Thetension rods 81 also expand as they absorb heat from the walls. Shortlengths of bar stock 93 are welded to the angles 92 to support theweight of the tension rods 81. However, the tension rods 81 are notsecured to the walls 11 and are otherwise independently suspended.

As is shown in FIGURE 1, sheet insulation 94 is fitted against the walls11 and around the clips 77 and the tension rods 81. On the outside ofthe I-beams, a covering 95 preferably of corrugated sheet metal is usedto enclose the unit. At every corner a removable shield 96 is used tocomplete the enclosure.

Although the invention has been described in its preferred form with acertain degree of particularity, it is understood that the presentdisclosure of the preferred form has been made only by way of exampleand that numerous changes in the details of construction and thecombination and arrangement of parts may be resorted to withoutdeparting from the spirit and scope of the invention is hereinafterclaimed.

What is claimed is:

1. A vapor generator or the like comprising:

a first pair of oppositely disposed vertical walls;

a second pair of oppositely disposed vertical walls extending betweensaid first pair of walls and joined thereto to define a chamber for hotgases;

buckstays extending transversely adjacent each of said walls, each ofsaid buckstays having end portions which extend beyond the ends of thecorresponding wall;

means supporting said buckstays in a spaced relationship to said walls,said supporting means including means to permit differential transversethermal expansion between said walls and said buckstays;

a first pair of tension rods having a circular cross section andextending adjacent said first pair of walls and connected to thecorresponding end portions of the buckstays adjacent said second pair ofwalls; and

a second pair of tension rods extending adjacent said second pair ofwalls and connected to the corresponding end portions of the buckstaysadjacent said first pair of walls, said first pair of tension rods andsaid second pair of tension rods lying in a common plane; and turnbucklemeans on said tension rods to permit crossing of said tension rods insaid common plane adjacent the junction of said first and secondvertical walls.

2. A furnace for a steam generator or the like as set forth in claim 1wherein said means for supporting said buckstays in spaced relationshipto said walls includes two pairs of interlocking L-shaped clips.

3. A vapor generator or the like comprising:

a first pair of oppositely disposed vertical walls;

a second pair of oppositely disposed vertical walls extending betweensaid first pair of walls and joined thereto to define a chamber for hotgases;

a first pair of I-beams extending transversely adjacent each of saidfirst pair of walls, each of said first pair of I-beams having endportions which extend beyond the ends of the corresponding wall;

a second pair of I-beams extending transversely adjacent each of saidsecond pair of walls, each of said second pair of I-beams having endportions which extend beyond the ends of the corresponding wall, saidfirst pair and said second pair of I-beams having main webs lyingsubstantially in a common horizontal plane;

a first set of four tubular connectors, each one of said first setsecured to a separate end of each I-beam of said first pair of I-beams;

a second set of four tubular connectors, each one of said second setsecured to a separate end of each I- beam of said second pair ofI-beams, each tubular connector of both said first set and said secondset having a longitudinal axis which lies substantially in a horizontalplane and is substantially perpendicular to the corresponding wall ofthe I-beam to which the tubular connector is secured;

a first pair of tension rods having a circular cross section andextending adjacent said first pair of walls and through said second setof tubular connectors, the end portions of said first pair of tensionrods extending through said second set of tubular connectors and beingthreaded;

first set of nuts in meshing relationship with the threaded end portionsof said first pair of tension rods to draw said first pair of tensionrods in tension; second pair of tension rods having a circular crosssection and extending adjacent said second pair of walls and throughsaid second set of tubular connectors, the end portions of said secondpair of tension rods extending through said first set of tubularconnectors and being threaded, said first pair of tension rods and saidsecond pair of tension rods lying in a common plane; and turnbucklemeans on said tension rods to permit crossing of said tension rods insaid common plane adjacent the junction of said first and secondvertical walls;

means including two pairs of interlocking L-shaped clips to support saidI-beams in a spaced relationship to said walls and to permitdifferential transverse thermal expansion between said walls and saidbuckstays;

means including outside pair of L-shaped clips secured means secured tosaid outside pairs of L-shaped clips to retain said first and secondpairs of tension rods against the first and second pairs of verticalwalls.

References Cited by the Examiner UNITED STATES PATENTS 20 3,007,45511/1961 Lieb et a1. "122-6 8/1965 Engelhardt 1226 KENNETH W. SPRAGUE,Primary Examiner.

1. A VAPOR GENERATOR OR THE LIKE COMPRISING: A FIRST PAIR OF OPPOSITELYDISPOSED VERTICAL WALLS; A SECOND PAIR OF OPPOSITELY DISPOSED VERTICALWALLS EXTENDING BETWEEN SAID FIRST PAIR OF WALLS AND JOINED THERETO TODEFINE A CHAMBER FOR HOT GASES; BUCKSTAYS EXTENDING TRANSVERSELYADJACENT EACH OF SAID WALLS, EACH OF SAID BUCKSTAYS HAVING END PORTIONSWHICH EXTEND BEYOND THE ENDS OF THE CORRESPONDING WALL; MEANS SUPPORTINGSAID BUCKSTAYS IN A SPACED RELATIONSHIP TO SAID WALLS, SAID SUPPORTINGMEANS INCLUDING MEANS TO PERMIT DIFFERENTIAL TRANSVERSE THERMALEXPANSION BETWEEN SAID WALLS AND SAID BUCKSTAYS; A FIRST PAIR OF TENSIONRODS HAVING A CIRCULAR CROSS SECTION AND EXTENDING ADJACENT SAID FIRSTPAIR OF WALLS AND CONNECTED TO THE CORRESPONDING END PORTIONS OF THEBUCKSTAYS ADJACENT SAID SECOND PAIR OF WALLS; AND A SECOND PAIR OFTENSION RODS EXTENDING ADJACENT SAID SECOND PAIR OF WALLS AND CONNECTEDTO THE CORRESPONDING END PORTIONS OF THE BUCKSTAYS ADJACENT SAID FIRSTPAIR OF WALLS, SAID FIRST PAIR OF TENSION RODS AND SAID SECOND PAIR OFTENSION RODS LYING IN A COMMON PLANE; AND TURNBUCKLE MEANS ON SAIDTENSION RODS TO PERMIT CROSSING OF SAID TENSION RODS IN SAID COMMONPLANE ADJACENT THE JUNCTION OF SAID FIRST AND SECOND VERTICAL WALLS.